Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Cadillac >> 2024 >> LYRIQ Tech, AWD >> Repair and Diagnosis >> Body & Frame >> Fixed And MOVEABLE Windows >> Diagnostic Information and Procedures >> Power Windows Malfunction >> Circuit/System Testing

Circuit/System Testing

Test 1

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: X1 @ S79D Front Side Door Window Control Switch-Driver
  3. Verify a test lamp illuminates between ground circuit terminal 1 and B+.
    • If the test lamp does not illuminate 
    1. Repair the open/high resistance on circuit 2150 or the ground connection.
    • Go to next step: If the test lamp illuminates 
  4. Ignition - On / Vehicle - In Service Mode
  5. Verify a test lamp Illuminates between B+ circuit terminal 8 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Test the B+ circuit 3840/4240 for an open/high resistance.
      • if an open/high resistance is found, repair the fault on the circuit.
      • Go to next step: If an open or high resistance is not found
    2. Verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Test the B+ circuit 3840/4240 for a short to ground
      • If a short to ground is found, repair the fault on the circuit.
      • Go to next step: If a short to ground is not found
    2. Replace the S79D Front Side Door Window Control Switch-Driver
    • Go to next step: If the test lamp illuminates 
  6. Ignition OFF, Connect the electrical connector X1 @ S79D Front Side Door Window Control Switch-Driver
  7. Disconnect the electrical connector: M74D Front Side Door Window Regulator Motor-Driver
  8. Connect a test lamp between the test points: Signal circuit terminal 3 & B+
  9. Ignition - On / Vehicle - In Service Mode
  10. Operate the component: Driver Left Front Window Switch @ S79D Front Side Door Window Control Switch-Driver - Pulled

    Verify the test lamp state:

    Driver Left Front Window Switch - Not Used = Test lamp Off

    Driver Left Front Window Switch - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X1 at the S79D Front Side Door Window Control Switch-Driver
    2. Test for infinite resistance between the signal 2763 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 2763 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79D Front Side Door Window Control Switch-Driver
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X1 at the S79D Front Side Door Window Control Switch-Driver, ignition ON.
    2. Test for less than 1 V between the signal 2763 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79D Front Side Door Window Control Switch-Driver
    • Go to next step: If the test lamp turns ON and OFF 
  11. Connect a test lamp between the test points: Signal circuit terminal 7 & B+
  12. Ignition - On / Vehicle - In Service Mode
  13. Operate the component: Driver Left Front Window Switch @ S79D Front Side Door Window Control Switch-Driver - Pressed

    Verify the test lamp state:

    Driver Left Front Window Switch - Not Used = Test lamp Off

    Driver Left Front Window Switch - Pressed = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X1 at the S79D Front Side Door Window Control Switch-Driver
    2. Test for infinite resistance between the signal 2764 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 2764 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79D Front Side Door Window Control Switch-Driver
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X1 at the S79D Front Side Door Window Control Switch-Driver, ignition ON.
    2. Test for less than 1 V between the signal 2764 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79D Front Side Door Window Control Switch-Driver.
    • Go to next step: If the test lamp turns ON and OFF 
  14. Connect a test lamp between the test points: Signal circuit terminal 5 & B+
  15. Ignition - On / Vehicle - In Service Mode
  16. Operate the component: Driver Left Front Window Switch @ S79D Front Side Door Window Control Switch-Driver - Pressed & Pulled

    Verify the test lamp state:

    Driver Left Front Window Switch - Not Used = Test lamp Off

    Driver Left Front Window Switch - Pressed = Test lamp On

    Driver Left Front Window Switch - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X2 at the S79D Front Side Door Window Control Switch-Driver
    2. Test for infinite resistance between the signal 2766 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 2766 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79D Front Side Door Window Control Switch-Driver
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X2 at the S79D Front Side Door Window Control Switch-Driver, ignition ON.
    2. Test for less than 1 V between the signal 2766 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79D Front Side Door Window Control Switch-Driver.
    • Go to next step: If the test lamp turns ON and OFF 
  17. Test or replace the component: M74D Front Side Door Window Regulator Motor-Driver

Test 2

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: X1 @ S79P Front Side Door Window Switch - Passenger
  3. Verify a test lamp illuminates between ground circuit terminal 1 and B+.
    • If the test lamp does not illuminate 
    1. Repair the open/high resistance on circuit 2050 or the ground connection.
    • Go to next step: If the test lamp illuminates 
  4. Ignition - On / Vehicle - In Service Mode
  5. Verify a test lamp Illuminates between B+ circuit terminal 8 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Test the B+ circuit 3840/4240 for an open/high resistance.
      • if an open/high resistance is found, repair the fault on the circuit.
      • Go to next step: If an open or high resistance is not found
    2. Verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Test the B+ circuit 3840/4240 for a short to ground
      • If a short to ground is found, repair the fault on the circuit.
      • Go to next step: If a short to ground is not found
    2. Replace the S79D Front Side Door Window Control Switch-Driver
    • Go to next step: If the test lamp illuminates 
  6. Ignition OFF. Connect the electrical connector X1 @ S79P Front Side Door Window Switch - Passenger
  7. Disconnect the electrical connector: M74P Front Side Door Window Regulator Motor-Passenger
  8. Connect a test lamp between the test points: Signal circuit terminal 3 & B+
  9. Ignition - On / Vehicle - In Service Mode
  10. Operate the component: S79P Front Side Door Window Switch - Passenger - Pulled

    Verify the test lamp state:

    S79P Front Side Door Window Switch - Passenger - Not Used = Test lamp Off

    S79P Front Side Door Window Switch - Passenger - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X1 at the S79P Front Side Door Window Switch-Passenger
    2. Test for infinite resistance between the signal 1184 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 1184 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79P Front Side Door Window Switch-Passenger
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X1 at the S79P Front Side Door Window Switch-Passenger ignition ON.
    2. Test for less than 1 V between the signal 1184 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79P Front Side Door Window Switch-Passenger
    • Go to next step: If the test lamp turns ON and OFF 
  11. Connect a test lamp between the test points: Signal circuit terminal 7 & B+
  12. Ignition - On / Vehicle - In Service Mode
  13. Operate the component: S79P Front Side Door Window Switch - Passenger - Pressed

    Verify the test lamp state:

    S79P Front Side Door Window Switch - Passenger - Not Used = Test lamp Off

    S79P Front Side Door Window Switch - Passenger - Pressed = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X1 at the S79P Front Side Door Window Switch-Passenger
    2. Test for infinite resistance between the signal 5295 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 5295 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79P Front Side Door Window Switch-Passenger
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X1 at the S79P Front Side Door Window Switch-Passenger, ignition ON.
    2. Test for less than 1 V between the signal 5295 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79P Front Side Door Window Switch-Passenger.
    • Go to next step: If the test lamp turns ON and OFF 
  14. Connect a test lamp between the test points: Signal circuit terminal 5 & B+
  15. Ignition - On / Vehicle - In Service Mode
  16. Operate the component: S79P Front Side Door Window Switch - Passenger - Pressed & Pulled

    Verify the test lamp state:

    S79P Front Side Door Window Switch - Passenger - Not Used = Test lamp Off

    S79P Front Side Door Window Switch - Passenger - Pressed = Test lamp On

    S79P Front Side Door Window Switch - Passenger - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X2 at the S79P Front Side Door Window Switch-Passenger
    2. Test for infinite resistance between the signal 2765 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 2765 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79P Front Side Door Window Switch-Passenger
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector X2 at the S79P Front Side Door Window Switch-Passenger, ignition ON.
    2. Test for less than 1 V between the signal 2765 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79P Front Side Door Window Switch-Passenger.
    • Go to next step: If the test lamp turns ON and OFF 
  17. Test or replace the component: M74P Front Side Door Window Regulator Motor-Passenger

Test 3

    NOTE:

    It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: S79LR Rear Side Door Window Switch-Left
  3. Verify a test lamp illuminates between ground circuit terminal 1 and B+.
    • If the test lamp does not illuminate 
    1. Repair the open/high resistance on circuit 2550 or the ground connection.
    • Go to next step: If the test lamp illuminates 
  4. Connect the electrical connector S79LR Rear Side Door Window Switch-Left
  5. Disconnect the electrical connector: M74LR Rear Side Door Window Regulator Motor-Left
  6. Connect a test lamp between the test points: Signal circuit terminal 3 & B+
  7. Ignition - On / Vehicle - In Service Mode
  8. Operate the component: S79LR Rear Side Door Window Switch-Left - Pulled

    Verify the test lamp state:

    S79LR Rear Side Door Window Switch-Left - Not Used = Test lamp Off

    S79LR Rear Side Door Window Switch-Left - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79LR Rear Side Door Window Switch-Left
    2. Test for infinite resistance between the signal 1185 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 1185 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79LR Rear Side Door Window Switch-Left
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79LR Rear Side Door Window Switch-Left ignition ON.
    2. Test for less than 1 V between the signal 1185 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79LR Rear Side Door Window Switch-Left
    • Go to next step: If the test lamp turns ON and OFF 
  9. Connect a test lamp between the test points: Signal circuit terminal 7 & B+
  10. Ignition - On / Vehicle - In Service Mode
  11. Operate the component: S79LR Rear Side Door Window Switch-Left - Pressed

    Verify the test lamp state:

    S79LR Rear Side Door Window Switch-Left - Not Used = Test lamp Off

    S79LR Rear Side Door Window Switch-Left - Pressed = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79LR Rear Side Door Window Switch-Left
    2. Test for infinite resistance between the signal 1187 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 1187 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79LR Rear Side Door Window Switch-Left
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79LR Rear Side Door Window Switch-Left, ignition ON.
    2. Test for less than 1 V between the signal 1187 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79LR Rear Side Door Window Switch-Left.
    • Go to next step: If the test lamp turns ON and OFF 
  12. Connect a test lamp between the test points: Signal circuit terminal 5 & B+
  13. Ignition - On / Vehicle - In Service Mode
  14. Operate the component: S79LR Rear Side Door Window Switch-Left - Pressed & Pulled

    Verify the test lamp state:

    S79LR Rear Side Door Window Switch-Left - Not Used = Test lamp Off

    S79LR Rear Side Door Window Switch-Left - Pressed = Test lamp On

    S79LR Rear Side Door Window Switch-Left - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79LR Rear Side Door Window Switch-Left
    2. Test for infinite resistance between the signal 5048 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 5048 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79LR Rear Side Door Window Switch-Left
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79LR Rear Side Door Window Switch-Left, ignition ON.
    2. Test for less than 1 V between the signal 5048 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79LR Rear Side Door Window Switch-Left.
    • Go to next step: If the test lamp turns ON and OFF 
  15. Test or replace the component: M74LR Rear Side Door Window Regulator Motor-Left

Test 4

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: S79RR Rear Side Door Window Switch-Right
  3. Verify a test lamp illuminates between ground circuit terminal 1 and B+.
    • If the test lamp does not illuminate 
    1. Repair the open/high resistance on circuit 2050 or the ground connection.
    • Go to next step: If the test lamp illuminates 
  4. Connect the electrical connector S79RR Rear Side Door Window Switch-Right
  5. Disconnect the electrical connector: M74RR Rear Side Door Window Regulator Motor-Right
  6. Connect a test lamp between the test points: Signal circuit terminal 3 & B+
  7. Ignition - On / Vehicle - In Service Mode
  8. Operate the component: S79RR Rear Side Door Window Switch-Right - Pulled

    Verify the test lamp state:

    S79RR Rear Side Door Window Switch-Right - Not Used = Test lamp Off

    S79RR Rear Side Door Window Switch-Right - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79RR Rear Side Door Window Switch-Right
    2. Test for infinite resistance between the signal 1186 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 1186 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79RR Rear Side Door Window Switch-Right
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79RR Rear Side Door Window Switch-Right ignition ON.
    2. Test for less than 1 V between the signal 1186 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79RR Rear Side Door Window Switch-Right
    • Go to next step: If the test lamp turns ON and OFF 
  9. Connect a test lamp between the test points: Signal circuit terminal 7 & B+
  10. Ignition - On / Vehicle - In Service Mode
  11. Operate the component: S79RR Rear Side Door Window Switch-Right - Pressed

    Verify the test lamp state:

    S79RR Rear Side Door Window Switch-Right - Not Used = Test lamp Off

    S79RR Rear Side Door Window Switch-Right - Pressed = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79RR Rear Side Door Window Switch-Right
    2. Test for infinite resistance between the signal 1188 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 1188 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79RR Rear Side Door Window Switch-Right
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79RR Rear Side Door Window Switch-Right, ignition ON.
    2. Test for less than 1 V between the signal 1188 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79RR Rear Side Door Window Switch-Right.
    • Go to next step: If the test lamp turns ON and OFF 
  12. Connect a test lamp between the test points: Signal circuit terminal 5 & B+
  13. Ignition - On / Vehicle - In Service Mode
  14. Operate the component: S79RR Rear Side Door Window Switch-Right - Pressed & Pulled

    Verify the test lamp state:

    S79RR Rear Side Door Window Switch-Right - Not Used = Test lamp Off

    S79RR Rear Side Door Window Switch-Right - Pressed = Test lamp On

    S79RR Rear Side Door Window Switch-Right - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79RR Rear Side Door Window Switch-Right
    2. Test for infinite resistance between the signal 5049 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 5049 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79RR Rear Side Door Window Switch-Right
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79RR Rear Side Door Window Switch-Right, ignition ON.
    2. Test for less than 1 V between the signal 5049 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79RR Rear Side Door Window Switch-Right.
    • Go to next step: If the test lamp turns ON and OFF 
  15. Test or replace the component: M74RR Rear Side Door Window Regulator Motor-Right
scientia non olet · About Mike's Workshop Manuals